The disciples wondered why they could not do what they had done before. They had cast out demons and healed people, but this boy was too much for them to accomplish.
Matthew 17:20 ESV
He said to them, “Because of your little faith. For truly, I say to you, if you have faith like a grain of mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move, and nothing will be impossible for you.”
